Association between body mass index and oocyte maturation in patients triggered with GnRH agonist who are at high risk for severe ovarian hyperstimulation syndrome: an observational cohort study.

ABSTRACT

RESEARCH QUESTION Is body-mass index (BMI) associated with oocyte maturation in women at high risk for developing severe ovarian hyperstimulation syndrome (OHSS) who are triggered with gonadotrophin releasing hormone (GnRH) agonist? DESIGN: Prospective observational cohort study. A total of 113 patients at high risk for severe OHSS (presence of at least 19 follicles ≥11 mm) pre-treated with gonadotrophin releasing hormone (GnRH) antagonists and recombinant FSH were administered 0.2 mg triptorelin to trigger final oocyte maturation. Patients were classified in two groups depending on their BMI ΒΜΙ less than 25 kg/m2 (n = 72) and ΒΜΙ 25 kg/m2 or over (n = 41). Baseline, ovarian stimulation and embryological characteristics, as well as luteal-phase hormone profiles, were compared in patients classified into the two BMI groups. The main outcome measure was the number of mature oocytes. RESULTS: A significantly higher number of mature (metaphase II) oocytes (19 [18-21] versus 16 [13-20], P = 0.029) was present in women with BMI less than 25 kg/m2 compared with those with BMI 25 kg/m2 or greater. The number of retrieved oocytes, the number of fertilized oocytes, oocyte retrieval, maturation and fertilization rates were similar in the two groups. A significantly higher dose of recombinant FSH was required for patients with BMI 25 kg/m2 or greater compared with patients with BMI less than 25 kg/m2 (1875 [1650-2150] IU versus 1650 [1600-1750] IU, P = 0.003) and the two groups displayed different luteal phase hormonal profiles. CONCLUSIONS: Among women at high risk for developing severe OHSS who are triggered with a standard dose (0.2 mg) of the GnRH agonist triptorelin, women with BMI 25 kg/m2 or greater had significantly fewer mature oocytes, required a higher total dose of recombinant FSH compared with women with BMI less than 25 kg/m2.